- Feb 28, 2006Hello Max,

Some simple partial results:

Let q=2^p-1; a=q²-q+1 then

q=0 mod 3, if p is even

q=1 mod 3, if p is odd (e.g. prime)

in any case a=1 mod 3

a is not divisible by 2,3,5; the more amazing that a=prime does not

occur (p>3).

a cannot be factorized within the real numbers such as e.g.

a²-b²=(a+b)*(a-b).

Werner - Next post in topic >>